The present disclosure relates to an information processing device, an information processing method, and a program, and specifically, it relates to an information processing device, an information recording medium, an information processing method, and a program capable of tracking the source of illegally distributed content.
A digital versatile disc (DVD) and a BLU-ray® Disc (BD) are widely used as an information recording medium (media) in which various contents such as a movie or music are recorded.
The copyright or the distribution right of many contents such as the image data or the music data recorded in these information recording media is possessed by an author or a seller. Therefore, in a case where such content is stored in the information recording medium (media) and supplied to users, generally, a control of use is performed such that only a user having a legitimate right of use is allowed to use the content.
Specifically, for example, a control is performed, in which the content is recorded as an encrypted content, and the content can be decrypted only by an encryption key that was provided to a user who made the legitimate purchasing process for the content. However, even if such a processing is performed, for example, if the user that acquired the encrypted content performs unauthorized processing to distribute or disclose the decrypted content or the encryption key to the public, illegal use of the content by an unspecified number of users occurs. Particularly, in recent years, there have been many cases of performance of illegal disclosure and delivery of the data via a network, and how to prevent such an illegal activity has become a major issue.
As one measure to prevent the illegal distribution of the content, there is a configuration that enables identification of a device which performed the decryption processing based on the decrypted content (plain text).
This is a configuration in which the device that performed the decryption processing can be identified based on identification data extracted from an image by analyzing the decrypted content generated by decrypting the encrypted content, for example, the decrypted image data.
The configuration enabling this source tracking is disclosed in Japanese Unexamined Patent Application Publication No. 2006-236121 and Japanese Unexamined Patent Application Publication No. 2007-43336.
The configurations disclosed in the above Patent Literature are configurations in which a segment that is configuring data of the content, for example, an image of a certain scene that configures the image content is set as a plurality of variation data that can be decrypted by different keys. Each reproduction device selects one data that can be decrypted from the plurality of variation data by applying a unique key which is stored in the reproduction device, and decrypts the data to reproduce. A reproduction device in which a different key is stored decrypts the image of the same scene using a different variation data and reproduces the decrypted data. In this way, different variation data is selected by each reproduction device and then the content is reproduced. That is, the reproduction processing is performed according to a reproduction path that is different depending on the reproduction device.
For example, in a case where copied data of the decrypted content is distributed via a network, by analyzing the variation data or the reproduction path included in the content, the device that decrypted the content can be identified to a certain range.
The encryption keys (decryption keys) stored in the reproduction device are different depending on the manufacturer of the device, and thus, it is possible to track the source (of illegal distribution) according to these units of setting.
However, for example, in a case where a movie content having the variation data is stored on a disc, it is necessary to record a plurality of images of the same scene that configures the variation data on the disc.
This causes a problem that a capacity of the data to be recorded on the disc increases.
Furthermore, in the reproduction processing, it is necessary to select one data from the image of the same scene recorded on the disc to reproduce, and thus, in the reproduction processing, it becomes necessary to perform the reproduction processing with a jump of a predetermined distance instead of the reproduction by continuous reading of the data recorded on the disc.
When the reproduction with the jump is performed as described above, the possibility that pauses in the reproduced image may occur increases.
In order to avoid the pauses in the reproduced image, it is necessary to perform processing of determining the arrangement of recorded data on the disc while considering the necessary jump time. However, since the data arrangement depends on the data length or the number of the variation data, there is a problem in that the difficulty in determining this data arrangement increases.